Patent GB-285481-A (GB)
IPC: H02J13/00
Filed: 1928-02-07
Abstract: 285,481. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Moreau, A. L.). Feb. 19, 1927, [Convention date]. Selective distant control systems; tell-tale apparatus.-In a system for the supervisory control of apparatus at a distant sub-station of the type wherein the apparatus, e.g. circuit-breakers and the corresponding control .keys and supervisory signals are associated successively with control and supervisory line wires by chains of synchronously operated relays which are driven over a third line wire, auxiliary relays are provided at each station and, when the relay chains are operating synchronously, are operated in series upon operation of corresponding chain relays to allow the synchronous operation to proceed. In the event of faulty operation, however, the auxiliary relays remain de-energized and bring about the restoration of the relay chains to normal. Furthermore in order that absolute svnchronism may be attained, the polarity of the driving-impulses and the polarity of energization and the circuit of the auxiliary relays are altered as the operations of the relay chains progresses. Figs. 1 and 2 show the control station apparatus and Figs. 3 and 4 show the equipment at the sub-station. The circuit-breakers 431 (one only being shown) and the corresponding keys 142 and supervisory lamps 135, 138 are connected to corresponding relays in the chains 412 - - 421, 161 - - 170. When the equipment is operated to change the position of a circuit-breaker, the relays are operated in succession until the relays corresponding to the circuit-breaker are operated when an impulse is transmitted over the line wire 290 to effect the desired operation. When the circuitbreaker changes its position an impulse is transmitted over the line 289 to operate the appropriate supervisory lamp. The relay chains are driven by relays 258, 336 which are energized in series over the line wire d. Auxiliaxy relays 263, 305 are energized in series after the operation of each relay in a chain, the arrangement being such that these relays are energized by alternate impulses of reverse polarity transmitted alternately over the line wires 289, 290. In the event of incorrect operation, the relays 263, 305 fail to operate and relays 160, 340 are energized to restore the selecting equipment to normal. Normal condition of system. The relays 224, Fig. 2, and 335, Fig. 3, are normally energized over the line wire 289. Normal operation of selective equipment. In order to effect the sequential operation of the relay chains a " start " key 204, Fig. 1, is depressed to energize relay 225 and as a result relay 229 which operates a relay 223 to close the circuit of the drive relays 258, 336 over the line wire d, opens the normal holding circuit of the relays 224, 335 and prepares the control and supervisory circuits. The control and supervisory line circuits and the drive-circuit are closed at the sub-station upon de-energization of the relay 335 by operation of relays 301, 306. The driverelays 258, 336 energize the first selecting relays 161, 412 which upon operation energize corresponding relays 101, 401 to prepare the circuits of the next selecting relays. The selecting relays 161, 412 also close a circuit over the line wire 290 for check relays 263, 305 which are energized only if synchronism exists. As a result, relays 228, 227, 302, 303 are energized to close further contacts in the control and supervisory circuits and relay 260 at the control station is energized to open the driving circuit to cause release of certain of the operated relays and thereby again close the driving circuit over the relays 258, 336. A similar cycle of operations is then performed, the driving impulses however energizing the selecting relays 162, 413 over the locked contacts of relays 101, 401. In this manner the selecting relays in each chain are closed and opened successively in synchronism. Synchronizing arrangements. In order to ensure synchronous operation, the nature of the checking and driving impulses and the circuit of the checking relays are altered upon the operation of each selecting relay. The contacts of the selecting relays are so connected that upon operation of the odd relays in each chain a checking impulse is transmitted from battery at the sub-station to earth at the control office and upon energization of the even relays an impulse is transmitted in the reverse direction. In addition, upon operation of the third relay in the selecting chains, relays 226, 304 are energized over the contacts of the relays 103, 403 to transfer the checking circuit from the line wire 290 to the wire 289. Operation of the fifth selecting relays fails to energize relays 226, 304 and the check circuit is again restored to line wire 290. This operation, i.e., the transmission of impulses of alternate polarity alternately over the lines 290, 289 is repeated throughout the sequential operations of the relay chains. Moreover the polarity of the driving impulses is reversed upon the operation of every fourth selecting relay. When relays 164, 415 are energized, relays 221, 308 are operated over parallel circuits. The relays 221, 308 prepare the circuits of relays 222, 307 which are operated just prior to operation of the fifth selecting relays, to reverse the battery connections to the drive line wire d. Just prior to the operation of the ninth selecting relays the relays 221, 308 are short-circuited to restore the original battery connections. Hence the polarity of the driveimpulses is reversed after the operation of every fourth selecting relay throughout the cycle of operations. A larger variety of checking impulses may be provided by employing in addition to the supervisory and control lines, the drive line d for transmitting impulses. Faulty operation of selecting equipment. If the system is not operating in synchronism the checking relays 263, 305 remain de-energized and a circuit is closed for relays 261, 339 which energize the release relays 160, 340 to restore the equipment to normal. Moreover, if two neighbouring selecting relays at the control office are operated simultaneously, relay 265 operates relay 264 which prevents energization of the checking relays and causes release. Relay 422 at the substation causes release under similar faulty conditions. The selecting equipment may also be released by manually controlled keys 209, 213. The keys close local circuits for the drive relays to initiate operation but open the checking circuit to prevent further operation and cause release. This arrangement also facilitates the release of the equipment after a particular selective operation without the necessity of complete operation of the relay chains. Operation of circuit-breaker. Assuming it is desired to close the circuit-breaker 431, the " stop " key 136 is operated. The selecting equipment is operated under the control of the " start " key 204 and the cycle proceeds in the manner previously described except that relay 260 is prevented from operation to cause energization of the selecting relays 162, 402 by operation of the " stop " key. The drive relays 258, 336 therefore remain energized and the apparatus remains inoperative with selecting relays 161, 401 operated. The master key 206 and individual control key 142 are then operated to close a circuit over the selecting relays and line wire 290 for relay 428 which causes the energization of solenoid 432 and closure of the circuit-breaker. Supervision. When the circuit-breaker changes its position slow-release relay 424 is de-energized to transmit an impulse over the line wire 289 and energize relay 156 which operates relay 212 to unlatch the armature 218 and thereby light the lamp 138 and extinguish the lamp 135, Relay 158 is also energized to prepare the supervisory circuit at the control station for the subsequent indication of the tripped position of the circuitbreaker. In the event of automatic operation of the circuit-breaker, operation of relays 424 - -426 energizes relay 334 which operates relay 301 to open the normal holding circuit and thereby initiate the sequential operation of the relay chains. Upon operation of the appropriate relays the supervisory indication of the changed conditions is recorded. Lamps 202, 205 are lighted during the normal and operative conditions of the system respectively and an additional lamp is provided for each selecting relay to indicate when the relay is operative.